Early scientific researchers hypothesized that electricity was an invisible fluid that could move through certain substances. Those substances "porous" to this "fluid" were called conductors, while substances impervious to this "fluid" were called insulators .
We now know what electricity is composed of: tiny bits of matter, smaller than atoms. What name do we give these tiny bits of matter? How do these particles of matter relate to whole atoms ?
In terms of these tiny particles, what is the difference between the atoms of conductive substances versus the atoms of insulating substances ? the atoms of insulating substances?